The invention relates to a mixing component of liquid crystal substances for the use in optoelectronic components for the rendition of numbers, symbols and images.
Nematic liquid crystals can be used in optoelectronic components (displays) for the modulation of passing through or reflected light, as well as for the rendition of numbers, symbols and images, see H. Kelker, R. Hatz, Handbook of Liquid Crystals, Publisher Chemie Seinheim, 1980.
Technically mostly mixtures of strongly positive dielectric anisotropy are required, which are also used in displays on the basis of the Schadt-Helfrich-effect (TNP-cells). The effect occurs only above a threshold voltage U.sub.o, of the following formula: ##EQU1## K.sub.ii =effective elastic constant .epsilon..sub.o =influence constant
.DELTA..epsilon.=dielectric anisotropy
The operating voltage, at which the displays have to be operated, lies higher than U.sub.o. It holds true, however, that the lower U.sub.o is, the lower is the operating voltage. By the optimization of liquid crystal mixtures for practical use, furthermore, many various parameters have to be taken into consideration, among others melting and clarification temperature, melting enthalpy, viscosity, optic and dielectric anisotropy, elastic constant. Frequently, a mixture meets the requirements in several characteristics, however, the dielectric anisotropy is too low, and consequently the threshold and operating voltage is too high.